I spent a little time down the hall at the Tile Council of North America testing lab last week. They were contemplating how they were going to physically move and test a 4’x 4’ tile weighing in at 120 pounds for size variation. Typically they use a computerized table with sensors to measure an 80 tile array for warpage, thickness, and size variation required under standards. Unfortunately this tile is as larger than the entire table and will definitely take two big strong people to position once they figure out what they will be measuring it with. Bigger is here to stay, so I expect we will be seeing some new equipment real soon.
Technology has been kind to the tile manufacturing industry. The development of ever larger tile continues to grow at a rapid pace. It is hard to believe that only 30 years ago making 12”x12” tile was a challenge for many plants. Part of the rapid growth in tile size is due to the number of new plants built to service the growing industry demand for ceramic tile in general. These plants are able to use the very latest in technological advances. This allows for the highly sophisticated and tightly controlled manufacturing process needed for the manufacture of today’s most popular products. Control rooms today resemble a jumbo jet cockpit using digital controls to monitor the entire production process complete with digital read outs, flashing lights, and alarm sirens. Glazing technology has also developed to a point unimagined years ago. Those of you who have been to Surfaces or Coverings were no doubt fascinated by the vendors providing laser etchings of any photo image to a tile body. Currently, the technology exists to transfer a full color picture to tile utilizing a process where glazing is applied in a fashion similar to the ink jet process and then fired to achieve a light commercial rating. It seems the innovation in the ceramic tile manufacturing process has no bounds.
On the installation side of the equation, tile and related product manufacturers have remembered the installers too. As one would expect, setting material manufacturers have developed many new products to aid in bonding big tile. While traditional commodity type thinset products may provide attributes that are still adequate for larger tile, in some instances they often lack the enhanced values need for today’s installation environment. Items that warrant considered include but are not limited to; the type and condition of the substrate, the desired drying time prior to traffic, the flatness of the substrate, environmental conditions of the job-site and the in service use of the ceramic tile floor. These conditions may require use of highly engineered latex or polymer modified products to meet real world conditions. Grout product selection seems to be undergoing some transition as well. Many end users are demanding “stain proof” grouts or those that offer consistent color. When you combine this hi-tech large sized tile and the trend of minimal code compliant wood structures problems can easily arise. Concrete placement and finishing techniques can pose a challenge as well all of which brings us to our next consideration.
The method used for preparation should be carefully considered. Attempting to correct out-of-plane conditions with thinset while installing tile is very labor intensive and often results in an unsatisfactory installation. Thinset is not designed for truing work of others, i.e. carpenters and masons. The thickness required for filling even a minor dip can often leave the thinset very weak and incapable of good bonding or support. Using thinset to level a floor makes as much sense as building a road out of mortar instead of concrete; it just doesn’t work or won’t for long. Self-leveling products are often used to correct deficiency in floor flatness. The term self-leveling is somewhat misleading. From personal experience I can tell you to choose your words carefully when describing what floor remediation products and application you will be using.
Tile industry recommendations require a flat surface, regardless of level conditions. A level surface is one which the bubble is center in a level. A flat surface is one where no daylight is seen under a straight edge; there is a big difference in both application and the amount of product used. Unless there are large areas of repair required, a floor patch may often be preferable. This type of surface remediation (prep) is often where the contractor or installer suffers financial abuse in correcting the work of others. In our company we always found the best and easiest way to get compensated for our work was to make remediation (prep) a whole separate issue and return to install another day. Telling someone you will need to use a medium bed mortar and a lot more of it to correct a floor problem provides no visual satisfaction that there was indeed more work and consequently it is often difficult to collect your just rewards. Having a flat surface also speeds installation and reduces material needs enhancing profits. As a contractor we always made remediation (prep) a separate operation. This may be a little more challenging in the installer ranks depending on the structure of things, but it certainly is more profitable. And why do I keep saying remediation (prep)? Well, if you were a customer, which would you rather pay for, remediation of deficient substrates or floor prep? It is easier and more accurate to get paid for remediation.
The considerations are many and more complex than many realize. Without argument the most important part of the process is making sure the tile is fully embedded in the thinset. Many often use a shortcut intended for non-wet walls called spot bonding. This has led to an ever increasing number of complaints for numerous reasons. Under certain conditions, spot bonding may work on walls given they are not expected to support loads. This is not true for floors which are load bearing surfaces. When troweling mortar for any application, the minor variation of the substrate and natural warpage of the tile or even the backing may mandate an application of mortar to the back of the tile, which is called backbuttering. Spot bonding is not appropriate for use regardless of whether back buttered or not. Based on phone calls and field visits for problems, it appears to be an increasingly popular method which is unfortunate once a claim is made.
The application and usage considerations of large unit tile are many. Such tile is often sold without regard for the inevitable substrate preparation required for satisfactory lippage-free installations. Small grout joints deserve consideration for the same reason: large tile’s inability to conform to floor irregularities. Even if the perfect substrate presents itself, tile will always have an inherent amount of warpage and size variation. There are products that will simply not lend themselves closely spaced flat floors under any conditions. Bottom line, tile should be chosen carefully with all its limitations fully understood. Setting materials deserve the same consideration and should be based on both environmental considerations and in service expectations. Chose wisely for happy customers and profitable installations.